Fluid motor



March 26, 1940.

W. H. WIN EMAN FLUID MOTOR Filed Sept 28,

1936 2 Sheets-Sheet 1 15204972702: waae wt'fieman.

' 04M; A' W dflarrzey.

Patented Mar. 26, 1940 FLUID Moron Wade H. Wineman, Coolspring Township,La

Porte County, Ind, assignor to Sullivan Machinery Company, a corporationof Massachusetts Application September as, 1936, Serial No. 102,988

16 Claims.

My invention relates. to expansible chamber motors, and moreparticularly to expansible chamber motors of the type especially adaptedfor pumping and similar uses. From one aspect, more specifically, myinvention relates to improved distributing meansfor such motors, havingautomatic. actuation and, super-imposed thereon, means permitting manualintervention, and the effecting of piston reciprocation with shortenedstrokes'at times when full stroke operation may be impossible.

In the pumping of oil, it is very common to has a tendency to remain inthe pump cylinder and gradually to increase in quantity therein to sucha degree as to slow down the operation of the pumping motor, and then,if conditions are not remedied, to interrupt the operation of thepumping motor completely, necessitating pulling out of the pump. I havefound it possible, by providing means whereby the. stroke of the pumpingmotor may be shortened and the apparatus made entirely independent ofthe automatic control of the distributing devices thereof,

to clear out the sand from the pump cylinder and enable operation to beresumed. In a preferred form of the invention, in which a'pump- Ioperating motor having a fluid actuated distributing valveis employed, Iprovide means operable under manual control .whereby the normal movementof the pump-operating motor piston necessary to efiect. admission orventing of fluid, to effect valve throwing, need not take place in orderfor the direction of piston movement to be reversed. Preferably Iprovide means whereby both strokes of the motor piston'may be shortened,that is to say, means whereby the motor piston'may be causedtoreciprocatefwith a short stroke between points lower than its normalupper limit. and above its normal lower limit ofv movement. means, anunsanding operation can be most effectually accomplished.

It is an object of my invention to provide an improved expansiblechamber motor having means associated therewith whereby the unsanding ofa pump operated thereby may be effected. It. is another objectof myinvention to provide an improved expansible-chamber mo tor havingautomatic fluid distribution means and supplemental means whereby themotor may 'tion to provide animproved expansible-chamber By theprovision of suchv more fully appear.

motor having automatic fluid distribution means of the fluid actuatedtype, controlled by movement of the piston within the motor cylinder andhaving auxiliary, selectively operable means whereby the full lengthtravel of the piston may I be made unnecessary in orderto effect thereversal of the positions of the fluid-distributing valve. It isjyetanother object of my invention to provide an' improved form of manualcontrolling apparatus adapted to exercise a superseding control over thefluid distribution valve of a pumping motor,'and to makejthe said valvedirectly responsive to manual manipulation of the controlling meansprovided, and independent of'piston travel to the points which normallydetermine valve throwing. Other objects and advantages of the In, theaccompanying drawings, in which, for purposes of illustration, oneillustrative embodiment of my invention has been shown: it

Fig-1 is a front elevation'of a' pumping moto in which'my inventionisincorporated in an illustrative form. H I Fig. 2 is a sectional-view, aportion of the section,*that through the pumping cylinder, being takenupon the section line. 22 of Fig. 1, and the section through thedistributing valve proper being a section at right angles to the planeof the line 22. v

v Fig. 3 is an enlarged, fragmentary, sectional view, showing details ofthe distributing valve mechanism,.sim ilar to a portion of Fig. 2,showinvention will hereinafter ingthe distributing valve in a. differentposition. Figs. 5 and 6' are diagrammatic views showing supplementalcontrol valves, and the different positions thereof for shortening theupward and downward piston travels respectively.

' Referring to the drawings, and first to Fig. 1 thereof, it will beobserved that a suitable support, a fragment of which is shown at 2, isadapted to support a pumping motor,"generally designated 3. The motor 3vincludes an upper head 4, a lower head 5, and an elongated cylinder 6which maybe formed in one piecefor in a plurality of alined parts, asdesired. Suitable tension elements 6a connect the upper and lower headsl and; 5, and clamp the cylinder-6 between these heads. Cylinder 6 has'abore 1 in which the motor piston 8 is reciprocable. Pis ton 8' hasconnected to it a pistonrod 9 which extends througha suitable packing IB and is adapted u to 'actuate through an appropriate sucker rod line,not shown, a lift pump at the bottom of the well.

Piston 8 is single acting, and pressure admitted beneath the same raisesit; and its downward movements are caused by its own weight and by thatof the connected parts, when a reduction in pressure beneath the pistontakes place. Thelower end or head of the motor cylinder has therein afluid supply groove 13 to which motive fluid at an appropriate pressure,say 200 to 300 pounds per square inch, may be admitted through a fluidsupply connection l4. Spaced materially below the supply groove I3 is anexhaust groove [5, which is connected to an exhaust connection 16.Between the grooves I3 and I5 is another groove I! which is connected bya passage l8 to the space beneath the piston 8 in the cylinder l.Desirably the motor operates with back pressure, and the back pressureis predetermined in such a manner as to provide the necessaryretardation of the motor piston 8 and its suspended parts during thedown-strokes thereof. The upper end of the motor cylinder is providedwith an appropriately vent-valve-controlled connection with theatmosphere, the vent-valve control device being designated 19 and beingoperative to provide for breathing of the upper end of the cylinderduring normal motor operations, but cushioning and checking the motorpiston travel in the event of breakage of the sucker rod line, theblowing through ofa pump packing, or the like.

A suitable, cylindrical, sleeve-like member 2| is received in a steppedbore 22 in the lower cylinder head 5, and is provided with alinedinternal 7 bores 23 and 24, the latter being the longer and the smallerin diameter. The bore 24 extends for the full length of the portion ofthe sleeve 21 which is opposite the spaces I3, l5. and H; and ports 25connect the bore 24 with the space or groove l3, whi e ports 26 connectthe space or groove 15 with the bore 24; and the annular groove I! isconnected with the bore 24 as at 21. A lower head 28, having a reducedportion 29, is appropriately held to the bottom of cylinder headmemberi, opposite, and closing the bore 22; and its reduced portion 29fits into'and closes the lower end of the bore 24. As the sleeve 2! isnot a close fit for the lowermost portion of the bore 22, and as apassage 39 is provided connecting said lowermost portion of said borewith the bottom of the bore 24, the lower end of the bore 24 iscontinuously maintained at the same pressure that prevails in the grovel5, to-wit; motor back pressure. Within the bores 23 and 24 there isreciprocable a suitable fluid-distribution valve 32, said va veincluding an upper, larger, ringed head 33 fitting the bore 23, anintermediate, doubly-ringed head 34 fitting the bore 24, and a lowerringed head of the same diameter as the head 34, also fittingbore 24 anddesignated 35. Reduced portions 36 and 31 respectively connect the heads33 and 34 and the heads 34 and 35. A fluid-conducting groove 38surrounds the portion 31.

Obviously the motor back pressure acting continuously on the lower endof head 35 would maintain the distributing valve 32 in raised position(the position shown in Fig.4) unless a pressure sufficient to move thevalve downward were exerted upon the upper end of the head 33. For thepurpose of periodically exerting such a pressure upon said head, and ofventing the same at desired times, I have provided the means which Ishall now describe. The upper end of the member 2! is closed by asuitably secured head 43. Arranged centrally in the head 40 is a tubularmember 4! having an enlarged portion 42 at its lower end which providesa valve seat 43 surrounding the mouth of a passage 44. The upper end ofthe distributing valve 32 provides a yielding mounting for a valveelement 46 having a tapered, seat-engaging portion 41 adapted tocoactwith the stationary seat 43 and close off communication between thepassage 44 and the space, herein designated for convenience 48, abovethe valve head 33. The passage 44 is connected by appropriate tubing andcontrolling devices, hereinafter more fully described and generallydesignated 53, to a point of communication 5! with the cylinder bore '5adjacent the position occupied by the upper end of the motor piston 8near the end of the downstroke of the latter, a position in which it isdesired to shift the reciprocating distributing valve 32 to causeadmission, for the purpose of effecting a new working stroke.

The reciprocation of the distributing valve 32 is maintained trulyrectilinear and rotation of said valve aboutits axis is prevented, by aguide a rod, 53 fixed in the head 40, and a cooperating guide bore 5 2formed in the valve proper.

A hardened contact 55 is mounted in the upper end of the distributingvalve 32, which may very desirably be made of aluminum or other lightmaterial; andthis contact is adapted to engage the stem 53 of aspring-pressed valve member 51, which is normally maintained by a spring58 upon a seat 59 carried-by the head 40. The valve 51 is ported as attill, and when it is unseated by pressure against its stem by thecontact element 55, there is opened a passage between the space 5! abovethe valve and the space ,48 above the distributing valve .head 33,through an annular space 33 surrounding the stem 56 and through thepassages 63. The space BI is connected by suitable passage andcontrolling means, hereinafter more fully described and generallydesignated 65, with a point of communication 66 with the cylinder bore1, adjacent a point in. the latter which is uncovered by the lower endof the upwardly moving motor piston as said motor piston approaches thedesired upper limit of its stroke.

Disregarding, for the present, the special controlling means provided asparts of the structures 58 and 65'hereinabove mentioned, the mode ofoperation of this device would be as follows:

In the position of the distributing valve shown in Fig. 4, pressurefluid would be admitted from the groove l3 through the space 38surrounding the reduced portion 31 to the groove l1, and through thepassage 18 into the cylinder bore beneath the piston 3. Piston 8 thenbegins to move upward, and as it moves upward its lower end first passesabove the point of communication 5!. Motor fluid from the cylinder boreat working pressure of 209 to 300 pounds, approximately, then passesinto the connection 44, but since the valve is upon the seat 43, thefluid within the, passage 46 cannot attain access to the space 48, and,therefore, the distributing valve remains in its uppermost position. Themotion of the be subjected to inlet pressure upon its larger end 33while its smaller lower end is still'subjec-ted only to motor backpressure. Downward valve movement will be completed by pressure throughpassage This causes interruption of motor fluid sup-ply beneath themotor piston 8 and. a connection of the groove IT in communication withthe lower'end of the motor cylinder with the exhaust groove l5, and soexhaust takes piace; As exhaust takes place, of course, the pressure inthe space #8 is reduced, but this pressure is not reduced sufficientlytocause the distributing valve to resume the position of Fig.

this being due to the fact that the reduction in pressure at this timecan never be below that pressure which constantly prevails in the lowerend of the bore 24, and since the head 33 is larger than the head 35the; distributing valve will remain in the position of Fig. 2'. However,the pressure within the motor cylinder will 'fall suiilciently so thatthe weight of the piston,

by the spring 58 that it cannot be unseated by the pressure then withinthe space it. Accordingly the motor piston will continue its downwardmovement until its upper end pass'esbelow not resting upon the valveseat'43. It may be noted in-passing that as soon as ,the valve 32assumes its lower position, that shown inEigs.

2 and 3, the valve 5'! assumesaseated position which it maintains untilthe upward movement of distributing valve causes the contact 55 toengage the stem 55 and unseat the valve 51. It may be noted, moreover,that when the distributingvalve assumes its uppermost position, thevalve surf-ace il seats upon the seat 43' and maintains 1e passage 44sealed until fluid admitted past the valve 51 forces down thedistributing valve, and thereby causes an opening of the communicationbetween the passage, and the space 48. v

We have now traced a complete cycle of the pumping motor, and undernormal conditions this cycle of operations would be continued in-.definitely, provided a suitable back pressure were maintained andprovided motor fluid at a suitable supply pressure were continued to beprovided.

However, due to the frequent presence in the 1 Obviously the motor willnot stop immediately,

with this apparatus, though it. will slow down and may also operate withreduced stroke. U1 timately, however, actual interruption of theoporation might be possible, but even thenthe present apparatus wouldpreclude damage to the sucker rod line such as would be occasionedwerethe atmosphere.

some other forms of power supplied for the reciprocation of the pumpplunger. For example, if a working-beam type of pump were beingemployed, with the excess power which these devices normally have, ifthe .pump sanded up there would promptly be an elongation of the suckerrod line, which would ruin the same quite promptly.

means is provided in the mechanism herein I l'esed for the purpose ofpermitting the unsending of the pumpby churning the piston thereof upand down in such a manner as to get the sand inthe pump cylinder intosuspension and enable its discharge. Figs. 5 and 6 diagrammaticallyi-Illustrate this mechanism. In these anism, including a casing 10,having therein a hollow rotary valve ll providing diametrically oppositeports 12 and 73 and a right-angularly arranged port it", and having anoperating handie 75 is adaptedselectively to connect a space incommunication with the communication point fiiiand a space H, incommunication with the connection 65, or to connect the space H throughthe ports it. and Min the valve with another, space it, which isconnected as at 1'9 with a point 89 in. the cylinder bore which isuncovered quite early in the normal upward stroke-of the motor piston 8.

Before describing the mode of operation of this auxiliary controldevice, the structure of the control device associated with the passage44 will also be described. Referring to Fig. 5 again, it will be notedthat the point of communication 58 is connected witha three-way valvemechanism generally designatedtZ, and comprising a casing havingchambers 83, 84 and 35 therein, chamber '83 being in communication withthe point 5E, chamber 84 being connected with the passage i l, andchamber fifi'communicating with g The valve mechanism 82 includes ahollow rotary valve 86, having diametrical'ly opposite ports 58 andedand a right-anguiarly' arranged port 87. In the position of the deviceshown in Fig. 6, i. e. with the operating handle at in a horizontalposition, the passage M communicates with the atmosphere. With thehandle 90 vertical, as in Fig.5, the passage is placed in communicationwith the point 5! in; the cylinder through the mutually opposite 83' and89'.

to operate the motor with considerably shorter and more rapid strokes,and thereby churn upthe sand in the pump cylinder. and clear out thepump cy inder much more promptly. As-this latter methcd is moreconducive to an e r.y resumption of normal pumping operations,

. this will described at this point Assume the distributing valve 32 tobe in the position shown hand that admission is taking place to thecylinder from the supply-connected groove '53 through the space 33 andthe passage [8 leadto the lower end of the motor cylinder: the

pinupmotor piston 6 will then be moving up- 1 wardiy. and as soon as thelower end of thepump motor p ston 8 has passed above the connectionpoint 5i, cylinder pressure which then exists within the connection 19and the space 18 can, if the operator moves the handle 15 intotheposition shown in Fig.5, be caused to pass through the port it to theinterior of the valve 1 I, through the port 14, space H, and connection65, and through passages Kill and B3; and thedistributing valve will bemoved down to the position shown in Fig. 2, its downward movementcompleted as usual by pressure through passage 44; and the motor pistonwill not complete its normal upstroke. Now, moreover, it will not benecessary to allow the motor piston to travel all the Way down to itsnormal lowest position before its motion can be again reversed,,and ifthe con-.- trolling handle 90 be moved into the position shown in Fig.6, the distributing valve 32 will move at once from the position shownin Fig. 2 back to the position shown in Fig. 4, for the pressure holdingthe distributing valve in the position of Fig. 2 will be immediatelyvented to atmosphere, through the passage 44, chamber 84, port 8?, andthe hollow interior of the valve 86, port 89, chamber 35, and theatmospheric connection.

Now it will be evident, since the distributing valve 32 effects motorexhaust in its lower position and since said distributing valve may becaused to move from its lower position to its upper position merely byshifting the control handle 90 to the position thereof shown in 6, thatthe extent of downward movement of the motor piston may be made justabout as small as desired; and the upward strokes of the motor pistonmay also be made very short by moving the control lever E to theposition shown in Fig. 5. It may be said that between the connectionpoints 5! and 66, long or short piston strokes may be effected, thelength of the upstroke determined merely by selecting the time to throwthe handle E5 tothe position of Fig. 5, and the downstrokes beingterminable at will by throwing handle 90 to the position of Fig. 6. Allthatis necessary to obtain a normal operation of the pumping motor is toturn the two levers l5 and 90 to the positions shown in Fig. 1, and toleave them there, in which event the motor will operate upon its normalcycle with long strokes, and upon a rectangular cycle. It will beunderstood that during short-stroke operation the handles 15 and 90.

need to be thrown down horizontally only momentarily, and each is bestthrown down only when the other is substantially vertical.

From the foregoing description it will be apparent that I have providedan improved ar-.

rangement including an automatic distributing valve means, and means formanually rendering the automatic operation of said distributing valvemeans inoperative and permitting the effecting of the events of cut-offand admission almost absolutely at the will of the operator. It will beevident that the operator can stand at the two control handles 15 and 90and control the upward and downward movements of the motor piston insuch manner as to cause a rapid surging upwardly and downwardly of thepump piston, and thereby force into suspension the sand within thepumping cylinder and effect a discharge of that sand with the liquidwithin the pump. It will be evident that the structure is simple, andthat it is not subject to easy derangement; and that it permits not onlyunsanding but a testing of the motor operation in a very advantageousmanner. It will further be noted, bearing in mind the comparativelysmall number of strokes per minute of the motor disclosed,

that the improved control means'described permits controlling theindividual strokes of the motor, that is, each individual stroke can beindividually controlled as desired within the limits I above noted; andcontrol of any selected stroke or strokes is possible, as well ascontrol substantially irrespective of the position of the motor pistonin the cylinder; and control at will of venting of the valve throwingpressure by manual operation of handle 90 is independent of the usualautomatic piston control.

While in the foregoing description I have described, and in theaccompanying drawings illustrated, one embodiment which my invention mayassume in practice, it will be understood that said invention may assumemany other forms and be modified without departing from the spiritthereof, or the scope of the appended claims.

What I claim and desire to secure by Letters Patent is: p

1. In combination, a motor cylinder, a piston normally reciprocabletherein in a predetermined path, a distributing valve for said motor,fluid pressure throwing means for throwing said distributing valve oneach stroke of the piston in said predetermined path and governed bypiston movement, and means for effecting under manualcontrol upon anyselected stroke of the piston, throwing of said distributing valve atany time prior to the attainment by said motor piston to the normalvalve throwing positions thereof. i

2. In combination, in a motor, a cylinder, a piston reciprocabletherein, a fluid-actuated distributing valve for said motor, means forsubjecting one end of said distributing valve continuously to, pressure,means controlled by said motor piston for alternatively subjecting theopposite end of said distributing valve to cylinder pressure and ventingpressure therefrom, said valve thrown in one direction by the subjectingof said opposite end of said valve to cylinder pressure, and in theother direction by a venting of pressure acting upon said opposite endof said valve, and means under manual control and operative during anyselected cycle or cycles of said piston, for elfecting such subjectingand such venting prior to the attainment of said motor piston to therespective positions thereof at which such subjecting and such ventingnormally occur in the regular operating cycle of said motor.

3. In combination, in a motor, acylinder having one end thereofconstantly connected to atmosphere, a'piston in said cylinder, and meansfor alternatively subjecting the end of said motor piston more remotefrom said cylinder end alternatively to live pressure or to a backpressure materially. in excess of atmospheric pressure, including adistributing valve having one end thereof constantly subjected to motorback pressure and having means for subjecting the other .end thereofalternatively to the pressures at the ternatively admitting motive fluidbeneath said motor piston and connectng the space beneath said motorpiston to exhaust, means for subjectingone endof said distributing valvecontinuously to a pressure-above atmospheric pressure,

and means for alternatively subjecting the other end of said valve toatmospheric pressure orto pressure conditions within said motor cylinderbeneath said motor piston, including passages leading from saidlastmentioned end of said valve to spaced points in the motor cylinderand valves controlling said passages and respectively carried by andactuated by saidfluid distributing valve, and means under operatorcontrol for sub jecting said distributing valvelthrough portions of saidpassages to cylinderpressure or to atmospheric pressure prior to theattainment by said piston to the respective points of piston movement atwhich such connections are normally ef fected. I a

5. In combination, infla motor, a cylinder disposed at an angle with thehorizontal and having a single acting piston reciprocable therein, fluiddistribution means for alternatively admitting live pressure to .andexhausting pressure from said cylinder beneath said piston, saiddistribution means including a reciprocatorydis-v tributing valve havingone end-thereof constant-- ly subjected to motor back pressure andhaving means for subjecting the other 'end thereof alternatively toatmospheric pressure through the upper end of said motorv cylinder'andtopressure conditions beneath said motor piston, said means forsubjecting'including a pair of passages, one connecting the space abovesaid valve with a point in said motor cylinder uncovered by the lowerend of the upwardly moving motor piston comparatively late in theworking stroke thereof,

upper end of said motor cylinder and through a direct atmosphericconnection respectively, at

will. I

6. In combination; a verticallyedisposed motor cylinder, having thereina motor piston, a fluid distributing valve reciprocable parallel to saidworking stroke of said motor, and another 0011- trolled by avalve movedto open position by" said distributing valve when the latter is positioned to admit fluid to said. cylinder, the last-- mentioned passagecommunicating with the motor cylinder at a point uncovered by the lowerend of the upwardly moving piston comparative ly late in the workingstroke thereof, and means under operator control for connecting saidlast mentioned passage with said motor cylinder at a point uncovered bythe lower-end of the upwardly moving motor piston comparatively early inthe working stroke thereof, and'means ,for conmeeting said firstmentioned passage directly with atmosphere, at will.

7. In combination, in a pump operating motor,

a cylinder, a piston'reciprocable therein, and fluid distribution meansfor said motor including a valvemovablein opposite directions betweenadmission'and exhaust positions,.lmeans for continuous'ly. subjectingone end of said valve to a pressure in excess of atmospheric pressure,tending I to move said-valve to admission position, and means forselectively subjecting the other end of said valve alternately to'thepressure within said motor cylinder beneath said piston and toatmospheric pressure through the non-working end of said cylinder, tocause reciprocation of saidv-alve, including two passages, one of saidpassages extending from a point uncovered by the lower end of the motorpiston early in the working stroke thereof and having a controllingvalve therefor carried by said distributingva-lve, the other of saidpassages uncovered by the lower end of the upwardly moving pistoncomparatively late in the working stroke thereof, and having acontrolling valve unseated by the fluid distributng valve when thelatter is in fluid admission position, and means for shortstroking saidniotor including means under manual control and arranged in said firstmentioned passage for effecting a direct communication of said passageto the atmosphere irrespective of motor piston position, and means undermanual control associated with said second mentioned passage for placingthe same at will in communication with said motor cylinder at a pointuncovered by the lower end of the motor piston early in the normalupward travel thereof. 1 i

8. In combination, a motor cylinder, a piston 'reciprocable therein,a'distributing valve for said motor, fluid pressure throwing means forsaid valve operative. to effect vcutoif or admission when the motorpiston attains to predetermined positions in its strokes, and meansincluding cyllnder connectionsunder manual control for controlling'theindividual strokes of said motor and manipulable to cause cutofforadmission by said valve at any time prior to attainment by said pistonto said positions. I

9. In combination, a motor cylinder, a piston reciprocable therein, adistributing valve for said motor, fluid pressure throwing means forsaid valve controlled by said piston and operative to efiect admissionupon the attainment to a predetermined position in its non-workingstrokeby said motor piston, and means undermanual con trol for controlling theindividual strokes of said motor and manipulable to cause admission bysaid valve at any time prior to attainment by said piston tosuch'position upon but a single stroke, if desired. a

10. In combination, a motor cylinder, a piston reciprocable therein, adistributing valve for said motor, means controlled by, the motor pistonat predetermined positions of the latter for efliectmg valve throwing oneach piston stroke, and means operative under manual control afterpiston movement starts for a given stroke to efiect valve throwing atany time prior to the moment when the piston attains to one of suchpositions on such stroke.

11. In combination, a motor cylinder, a piston reciprocable therein, adistributing valve for said motor, means controlled by the motor pistonat predetermined positions of the latter for effectmg alve throwing oneach piston stroke, and means operative under manual control andactuatable between the times when the motor starts towards and reachesone of such positions, to effect pressure fluid valve throwing at anytime prior to the moment when the piston attains to such position.

12. In combination, a motor cylinder, a piston piston position, prior tothe moment when the piston attains to said predetermined position.

13. In combination, a motor cylinder, a piston reciprocable therein,distributing valve means for saidmotor, fluid pressure throwing meansfor throwing said distributing valve on each piston strokeand governedby piston movement, and manually operable means for effecting throwingof said distributing valve by fluid pressure irrespective of pistonposition, thereby controlling said valve means to provide forsubstantially any stroke between full stroke and a stroke a smallfraction of full stroke.

14. In combination, a motor cylinder, a piston reciprocable therein, adistributing valve for said motor, controlling means for said valveoperative to effect throwing thereof under piston controlled 'fluidsupply and venting, and means for efiecting at will the ventingindependently of piston control.

, 15. In a motor, in combination, a cylinder, a piston reciprocabletherein, a distributing valve for said motor controlling admission ofworking fluid thereto, controlling means for said distributing valveincluding a pressure area acting to move said valve to open position,means for conducting pressure-fluid to said area and venting pressuretherefrom including connections to said cylinder, valves for controllingsaid connections and respectively actuated-by andcarried by saiddistributing valve, and manually operable means ior controlling theconnections of said pressure fluid conducting means to said cylinder.

16. In combination, a motor cylinder, a piston reciprocable therein, adistributing valve for said motor, throwing means for said valverendered effective on venting'of said distributing valve to atmosphereand operative to efiect admission upon the attainment to a predeterminedposi-- tion in its non-working stroke by said motor pis ton, and meansunder manual control for venting said distributing valve to atmosphereat any time during the non-working stroke of said motor piston prior toattainment by said piston to such position. i

WADEH.

